Glassware such as glass houseware may slide on smooth surfaces such as a countertop or table causing damage to the smooth surfaces as well as possible spillage of the contents of the glassware. Various devices have been employed in an attempt to prevent or minimize this tendency. For example, an india rubber ring has been placed in a recess on the bottom of hollow ware. The india rubber ring forms a non-slip barrier between the hollow ware and furniture or other surfaces upon which the item is to be rested. However, use of india rubber in connection with glassware has numerous disadvantages. For example, india rubber has significant disadvantages with respect to its use in high temperature applications. In particular, india rubber is susceptible to deformation and melting when subjected to high temperatures, thereby limiting its effective use on glassware used in conventional ovens, microwaves and other high temperature environments. Accordingly, there exists a need for glassware having a non-slip surface which can be used in both low and high temperature environment.
Silicone generally exhibits good non-slip characteristics, has a high tolerance to elevated temperatures and readily accepts colorants and dyes. While it is believed that elastomers such as silicone have been used to some degree on ceramics, ceramic dishware inherently has certain limitations. In particular, the brittleness and certain physical and thermal characteristics of ceramic dishware, not generally associated with glass dishware, make the use of ceramic dishware undesirable and impractical in certain cooking applications. Moreover, use of silicone as a non-slip surface for ceramic products has several disadvantages. For example, silicone has very limited natural adhesion to ceramic material. Accordingly, it is often necessary to apply an intermediate glass-like coating to the ceramic item to achieve some degree of adhesion between the silicone and the ceramic. The need for such an intermediate agent to provide the necessary bonding characteristics creates a potentially less reliable adhesion, and increases overall product cost and manufacturing time. Therefore, a needs exists to provide for a substantially homogenous glass dish with a silicone support that adheres directly to the dish without an intermediate adhesive or bonding agent.
It is also known to apply silicone to glass to provide a protective surface for fragile glassware items as for example is shown in U.S. Pat. No. 4,860,906 to Pellegrini et al. U.S. Pat. No. 4,860,906 is directed to a thin-walled glass container that is subjected to intermittent periods of rapid heating and cooling, wherein preferably substantially the entire exterior surface of the glass container is coated by a silicone elastomer safety applied thereto by using conventional dipping and spraying techniques. While the application of silicone to glass described in U.S. Pat. No. 4,860,906 is suitable for protecting thin glassware from breakage, the use of silicone described therein has significant disadvantages in non-slip applications in which a coating is not required or desirable.
For example, the use of silicone coating as a non-slip surface for glassware can be costly in view of the relative material costs, particularly if the silicone is applied using traditional dipping, spraying or coating techniques such as is taught by U.S. Pat. No. 4,860,906. Moreover, certain difficulties arise when attempting to use a targeted silicone appliqué as a non-slip surface, that may not occur with silicone coatings such as that described in U.S. Pat. No. 4,860,906. In particular, silicone has an undesirable tendency to peel away from glass when shear forces are applied thereto, thereby exposing both the glassware and the silicone to damage. Glassware such as houseware is also typically subjected to extensive wear during ordinary use that may result in the silicone suffering mechanical damage. Thus, a need exists to minimize the quantity of silicone used, while providing sufficient silicone to benefit from desirable non-slip qualities of silicone. A need also exists to provide a mechanism that protects the silicone application from physical damage in finished glassware products.
The present invention is provided to solve the problems discussed above and other problems, and to provide advantages and aspects not provided by prior glassware. A full discussion of the features and advantages of the present invention is deferred to the following detailed description, which proceeds with reference to the accompanying drawings.